In the rich text editor:
@Lantams
In a comment:
[Lantams](https://chowlings.com/user/Lantams)
For Names and Avatars:
In the rich text editor:
%Lantams
In a comment:
[![Lantams's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/Lantams) [Lantams](https://chowlings.com/user/Lantams)